The Pokémon Go Plus finally launched this week with a previously unknown feature that makes the $35 accessory infinitely more useful to gameplay. Its new ability to track distance in the background means that users don’t have to keep the app open to hatch Eggs or gain Candy with Buddy Pokémon.

Announced last Friday, the latest version of Pokémon Go with the new Buddy feature is rolling out now. Version 0.37.0 for Android and 1.7.0 for iOS also includes fixes for many common bugs and support for the Pokémon Go Plus accessory launching next week.

After unveiling an Apple Watch version of the widely popular AR mobile game at Apple’s iPhone event, Niantic Labs has now announced on the Pokémon GO blog that the physical companion accessory, the Pokémon GO Plus, will begin shipping out to fans on September 16.

With its international rollout under way, Pokemon Go has reached 50 million downloads on Google Play this weekend. According to app firm Sensor Tower, it is the fastest game to exceed 50 million installs and is currently still the top free Android app. Also, while server issues and other bugs have died down, Nintendo is seemingly delaying the Pokemon Go Plus wearable accessory until September…

After opening sign-ups two weeks ago, the US Field Test of Pokémon GO begins today. The Pokémon Company and Niantic Labs revealed more information about the mechanics of the real world game. Pokémon GO will have in-app purchases and sell a Bluetooth wearable that notifies users of in-game events.

Today, the Pokémon Company has announced that it is partnering with Nintendo and Alphabet-owned Niantic to produce a new upcoming mobile game called Pokémon Go. This title will be available on both iOS and Android devices for free. The main focus of the game is collecting, training and battling Pokémon characters against other users based on their GPS location.

However, this new adventure will be supplemented by an optional wearable. Imagine a Pokémon smart watch of sorts.

This new wearable is called Pokémon Go Plus. It connects to your smartphone via Bluetooth and flashes its built-in LED light to notify you of nearby players as well as virtual Pokémon you can catch. For example, say you’re on your morning commute on the subway. Pokémon Go Pluswill ping your wrist to let you know that a virtual Charizard is closely located. After capturing, you’ll be able to train and battle with that new character.

The wearable isn’t required to play the game but it is an unique add-on that bring another level to the experience. Be sure to check out the video above for a visual representation of how game play works. Pokémon Go will be released on iOS and Android in 2016 as a free download with in-app purchases. Pricing has yet to be released for the Pokémon Go Plus Wearable. The entire press conference and announcement has been uploaded to YouTube for viewing, as well.